Loaded signaling conductor



LOADED S IGNALING CONDUCTOR Fi'led Dec. 24, 1920 Patented Feb. 24, 1925.

UNITED STATES PATENT OFFICE.

GUSTAF W. ELMEN, OF LEONIA, NEW JERSEY, ASSIGNOR TO WESTERN ELECTRIC COMPANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

LOADED SIGNALING CONDUCTOR.

Application filed December 24, 1920. Serial No. 432,980.

To all whom it may concern:

Be it known that I, GUSTAF W. ELMEN, a citizen of the United States, residing at Leonia, in the coimty of Bergen, State of New Jersey, have invented certain new and useful Improvements in Loaded Signaling Conductors, of which the following is a full, clear, concise, and exactdescription.

This invention relates to loaded signaling conductors such as are used, for instance, in submar'r e cable signaling.

It is e e object of this invention to provide a novel method of producing a signaling conductor having inductive loading consisting of an adherent coating or sheathing of magnetic material.

Another object of the invention is to provide a novel form of loaded signaling conductor of the'type in which the loading material forms'a coating or sheathing adherent to the conductor.

Other objects and features of the invention will appear from a consideration of the following description taken in connection with the drawing and the appended claims.

The figure of the drawing shows a perspective view of a cable end from which projects one of the signaling conductors loaded in accordance with this invention There are two generally recognized methods of loading signaling conductors. Perhaps the more extensively used method is that of inserting so-called loading coils at intervals in the circuit. The other method is generally called continuous loading. In either method of loading the object is the same, namely, to introduce an amount of inductance per unit length which will satisfy the condition of approximately distortionless transmission of an alternating or pulsating electric current.

Both in the case of loading coils and in the case of continuously loaded conductors, the electrical characteristics which it is desir able to have in the magnetic material used for loading are the same. These characteristics are high specific resistance to keep down the eddy currents in the loading material, extremely low hysteresis loss, magnetic stability or constancy in permeability as regards signaling currents even though large currents are superposed on the circuit, and as high permeability at low magnetizing forces as is consistent with the foregoing characteristics.

The use of tape or wire, heretofore used for continuous loading, is not without its disadvantages. Ithas been found in this connection that if the loading material be applied in such a way as to grip the conductor too tightly, the resulting strain greatly reduces the permeability of the loading material. If on the other hand the loading material be applied so loosely as to leave even small interstices between the successive windings, pressure, especially in the case of submarine cables, tends to force the insulatlng covering between the conducting core and the loading material, thus impairing the efliciency of the cable. In any case, it has proven impossible to prevent the introduction of air gaps between the successive windings, and hence, a reduction in the effective inductance has resulted.

It has been found that the high permeability of iron-nickel alloys renders them particularly adaptable for use as a loading material for signaling conductors, and Gustaf W. Elmens pending application Serial No. 473,877, which is a continuation of application Serial No. 111,080, discloses one method of using this property to advantage. In accordance with the present invention an alloy of iron and nickel, preferably contain ing at least 20% of nickel is formed about a comparatively short piece of copper or other metal adapted to serve as a conductor of signaling currents. This composite structure comprising a metal surrounded by an alloy is then drawn into a wire by swaging or by any other approved method. The resulting structure will be a wire having a continuous sheathing which adheres permanently to a metal core, the diameter of the structure being constant throughout its length.

As a result of the mechanical working of the compound bar in order to draw it into a wire, the permeability of the covering of iron-nickel alloy is decreased. In order to increase the permeability of this covering material, after the compound wire has been drawn, it is subjected to a predetermined degree of heat. The structure may be heated in any approved method in order to increase the permeability, but the process is preferably carried out in accordance with the method disclosed in G. W. Elmens application Serial No. 17 3,877 which is a continuation of application Serial No. 111,080.

Although the invention herein described is particularly suitable for use as a continuously loaded signaling conductor, it can obviously be used also in any case where a conductor of this general type is of use. The claims have been drawn with this in mind.

The term adherent as used in certain of the claims to specify the type of coating signifies one which is attached at its surface of contact.

What is claimed is:

1. The method of producing a continuously loaded signaling conductor which consists in elongating a compound bar of a metal and a magnetic alloy.

2. The method of producing a continuously loaded signaling conductor which consists in elongating a compound bar of a metal and an iron-nickel alloy.

3. The method of producing a continuously loaded signalin conductor which consists in forming an alloy of iron and nickel about a conducting core, the nickel comprising at least 20% of the alloy, and subse quently drawing the compound bar.

4. The method of producing a continuously loaded signaling conductor which consists in drawing a bar comprising a conducting core surrounded by an iron-nickel alloy, and subsequently subjecting the structure to a heat treatment to increase the permeability.

5. The method of producing a continuously loaded conductor which consists in drawing a bar comprising a conducting core surrounded by an iron-nickel alloy, the nickel comprising at least 20% of the alloy, and subsequently subjecting the structure to a heat treatment to increase the permeability.

6. The method of producing a continuously loaded signaling conductor which consists in forming an alloy of iron and nickel about a conducting core, the nickel comprising at, least 20% of the alloy, drawing the compound bar, and subsequently subjecting the structure to a heat treatment to increase the permeability of the alloy.

7. The method of producing a signaling conductor continuously loaded with an alloy capable of being given high permeability, comprising the steps of causing a coating of the alloy to adhere to the surface of the conductor, reducing the over-all diameter of the coated conductor by drawing, and subsequently subjecting the structure to a heat treatment.

8. A. continuously loaded signaling conductor comprising a drawn wire having a conducting core surrounded by an adherent coating of magnetic alloy.

9. A continuously loaded signaling conductor comprising a conducting core sur rounded by an adherent coating or an alloy of nickel and iron the nickel comprising at least 20% of the alloy.

10. A continuously loaded signaling con ductor comprising a drawn wire having a conducting core surrounded by an adherent coating of a magnetic alloy having high permeability developed therein by heat treatment subsequent to drawing.

11. A continuously loaded signaling conductor comprising a conducting core surrounded by an adherent coating of an alloy of iron and nickel containing at least 20% of nickel, the whole being drawn and subse quently heat treated.

12. An electrical conductor comprising a central core of metal and a surrounding adherent coating of magnetic alloy comprising iron and nickel and of which the nickel forms at least 20%.

13. The combination with an element having high electric conductivity of inductance increasing meanscomprising a coating of nickel iron alloy containing at least 20% of nickelattachod to said element at its surface of contact.

In witness whereof, I hereunto subscribe my name this 21st day of December, A. D. 1920.

GUSTAF W. ELMEN. 

